telotristat ethyl controls diarrhea for those whose diarrhea is serotonin produced. telotristat ethyl method of action is to inhibit seroatonin production.

On February 28, 2017, the U.S. Food and Drug Administration approved Xermelo in combination with somatostatin analog (SSA) therapy for the treatment of adults with diarrhea associated with carcinoid syndrome that SSA therapy alone has inadequately controlled.Xermelo is manufactured by Lexicon.